Sedimentary environment and reservoir characteristics of microbial carbonate rocks in Leikoupo Formation of Jiangyoutongkou Section

Abstract

As an important part of carbonate rocks, microbial rock is a good reservoir rock type, and its type characteristics and reservoir formation mechanism are different in different environments. By selecting Jiangyou Tongkou section in western Sichuan, the development environment and reservoir physical characteristics of typical microbial rock are analyzed, and the formation conditions of high-quality microbial rock reservoir are discussed. The results show that: The types of microbial rocks in the Leikoupo Formation of Jiangyou Tongkou Section are mainly tubbers and stromatolites, among which the second and fourth members of Leikoupo Formation are typical. They are developed in relatively warm and high salinity seawater, and their sedimentary environment is anaerobic environment with strong reductive property. The reservoir space types of microbial rocks are mostly intra (intergrain) void and grainy pore. In terms of reservoir physical properties, microbiolites are superior to non-microbiolites, and the 4th member of Lei Formation is the dominant reservoir of microbiolites.